Tag: Server management

Here’s a more extensive HTML table of common Linux commands with their usage and descriptions:

Command	Usage	Description
ls	ls [options] [directory]	Lists the contents of a directory.
cd	cd [directory]	Changes the current directory to the specified directory.
mkdir	mkdir [directory]	Creates a new directory.
rm	rm [options] [file]	Deletes files or directories.
rmdir	rmdir [directory]	Removes an empty directory.
cp	cp [options] source destination	Copies files or directories.
mv	mv [options] source destination	Moves or renames files or directories.
touch	touch [file]	Creates an empty file or updates the timestamp of an existing file.
chmod	chmod [options] mode file	Changes file permissions.
chown	chown [options] user[:group] file	Changes file owner and group.
ps	ps [options]	Displays information about active processes.
kill	kill [options] pid	Terminates a process by its ID.
df	df [options]	Shows disk space usage.
du	du [options] [directory]	Shows disk usage of files and directories.
tar	tar [options] file	Archives files.
gzip	gzip [file]	Compresses files.
gunzip	gunzip [file]	Decompresses gzip files.
zip	zip [options] zipfile files	Creates a compressed archive.
unzip	unzip [file.zip]	Extracts files from a zip archive.
wget	wget [options] url	Downloads files from the internet.
curl	curl [options] url	Transfers data from or to a server.
ping	ping [options] hostname	Checks the network connection to a server.
top	top	Displays real-time system processes and resource usage.
nano	nano [file]	Opens a file in the Nano text editor.
vim	vim [file]	Opens a file in the Vim text editor.
echo	echo [text]	Displays a line of text or variable value.
cat	cat [file]	Displays the content of a file.
less	less [file]	Views the content of a file page by page.
head	head [options] [file]	Displays the first lines of a file.
tail	tail [options] [file]	Displays the last lines of a file.
find	find [path] [options]	Searches for files in a directory hierarchy.
locate	locate [file]	Finds the location of a file.
man	man [command]	Displays the manual page for a command.
ssh	ssh [options] user@hostname	Connects to a remote server via SSH.
scp	scp [options] source destination	Copies files between hosts over SSH.
sudo	sudo [command]	Executes a command as another user, typically root.
apt-get	apt-get [options] command	Manages packages on Debian-based systems.
yum	yum [options] command	Manages packages on Red Hat-based systems.
systemctl	systemctl [command]	Controls the systemd system and service manager.
service	service [service] [command]	Manages system services.
passwd	passwd [options] [user]	Changes a user’s password.
adduser	adduser [options] user	Adds a new user to the system.
deluser	deluser [options] user	Removes a user from the system.
crontab	crontab [options] [file]	Schedules regular tasks with cron.
alias	alias name=’command’	Creates a shortcut for a command.
unalias	unalias name	Removes a command alias.
uname	uname [options]	Prints system information, such as the kernel name, version, and more.
hostname	hostname	Displays or sets the system’s hostname.
free	free [options]	Shows memory and swap usage.
df	df [options]	Shows disk space usage.
du	du [options] [directory]	Shows disk usage of files and directories.
history	history	Displays the list of previously executed commands.
uname	uname -a	Displays system information including the kernel version.
uptime	uptime	Shows how long the system has been running, including load averages.
who	who	Displays information about users currently logged into the system.
useradd	useradd [options] username	Adds a new user account.
usermod	usermod [options] username	Modifies a user account.
userdel	userdel [options] username	Deletes a user account.
groupadd	groupadd [options] groupname	Creates a new group.
groupdel	groupdel groupname	Deletes a group.
passwd	passwd [options] [username]	Changes a user’s password.
top	top	Displays real-time information about system processes and resource usage.
killall	killall [process name]	Terminates all processes with the specified name.
reboot	reboot	Reboots the system.
shutdown	shutdown [options] [time]	Shuts down the system.
mount	mount [options] device directory	Mounts a filesystem.
umount	umount [options] directory	Unmounts a filesystem.
fdisk	fdisk [options] device	Partition a hard disk.
mkfs	mkfs [options] device	Formats a filesystem on a device.
fsck	fsck [options] [filesystem]	Checks and repairs a filesystem.
df	df [options]	Reports the amount of disk space used and available on filesystems.
du	du [options] [directory]	Estimates file space usage.
ln	ln [options] source [target]	Creates hard and symbolic links between files.
tee	tee [options] [file]	Reads from standard input and writes to standard output and files.
chmod	chmod [options] mode file	Changes file modes or Access Control Lists (ACLs).
chown	chown [options] user[:group] file	Changes file owner and group.
chgrp	chgrp [options] group file	Changes the group ownership of a file.
dd	dd [options] [if=file] [of=file]	Converts and copies a file.
grep	grep [options] pattern [file]	Searches for patterns in files.
sed	sed [options] script [file]	Stream editor for filtering and transforming text.
awk	awk [options] ‘program’ [file]	A programming language that can be used for text processing and data extraction.
cut	cut [options] file	Removes sections from each line of files.
sort	sort [options] file	Sorts lines of text files.
uniq	uniq [options] file	Removes duplicate lines from a file.
diff	diff [options] file1 file2	Compares files line by line.
comm	comm [options] file1 file2	Compares two sorted files line by line.
head	head [options] [file]	Outputs the first part of files.
tail	tail [options] [file]	Outputs the last part of files.
paste	paste [options] file1 file2	Merges lines of files side by side.
tr	tr [options] set1 set2	Translates or deletes characters.
echo	echo [options] string	Displays a line of text.
expr	expr expression	Evaluates expressions.
bc	bc	An arbitrary precision calculator language.
xargs	xargs [options] [command]	Builds and executes command lines from standard input.
printf	printf [format] [arguments]	Formats and prints data.
date	date [options] [+format]	Displays or sets the system date and time.
cal	cal [options] [month] [year]	Displays a calendar.
uptime	uptime	Shows how long the system has been running.
whoami	whoami	Prints the current username.
env	env [options]	Displays or modifies the environment.
alias	alias name=’command’	Creates an alias for a command.
unalias	unalias name	Removes an alias.
export	export [variable]	Sets an environment variable.
unexport	unexport [variable]	Unsets an environment variable.
seq	seq [options] first last	Prints a sequence of numbers.
basename	basename [path] [suffix]	Strips directory and suffix from filenames.
dirname	dirname [path]	Strips the last component from a file path.
bc	bc [options]	Interactive algebraic language calculator.
yes	yes [string]	Outputs a string repeatedly until killed.
nohup	nohup command [arguments]	Runs a command immune to hangups.
sleep	sleep [number][suffix]	Delays for a specified amount of time.
bc	bc	Basic calculator with support for floating-point arithmetic.
clear	clear	Clears the terminal screen.
jobs	jobs	Lists the active jobs.
fg	fg [job]	Brings a job to the foreground.
bg	bg [job]	Resumes a suspended job in the background.
disown	disown [job]	Removes jobs from the job table.
type	type [command]	Describes how a command would be interpreted.
read	read [options] variable	Reads a line of input into a variable.
trap	trap [command] [signal]	Catches and handles signals.
wait	wait [pid]	Waits for processes to complete.
kill	kill [signal] pid	Sends a signal to a process.
pkill	pkill [options] pattern	Stops processes by name.
killall	killall [options] name	Kills processes by name.
bg	bg [job]	Resumes a job in the background.
fg	fg [job]	Brings a job to the foreground.
jobs	jobs	Lists background jobs.
alias	alias name=’command’	Creates a shortcut for a command.
unalias	unalias name	Removes an alias.
echo	echo [string]	Displays a line of text.
cal	cal [options] [month] [year]	Displays a calendar.
yes	yes [string]	Outputs a string until killed.
bc	bc [options]	Interactive calculator.
time	time [command]	Measures the duration of a command’s execution.
uptime	uptime	Shows how long the system has been running.
who	who	Displays who is logged in.
w	w	Shows who is logged in and what they are doing.
users	users	Shows the currently logged-in users.
last	last [options] [username]	Shows the last logins of users.
lastb	lastb [options]	Shows the last bad login attempts.
uname	uname [options]	Displays system information.
df	df [options]	Shows disk space usage.
du	du [options] [directory]	Shows disk usage.
lsof	lsof [options]	Lists open files and the processes using them.
strace	strace [options] command	Traces system calls and signals in a process.
nc (netcat)	nc [options] host port	Performs network operations, such as port scanning, or file transfer.
tcpdump	tcpdump [options]	Captures and analyzes network packets.
rsync	rsync [options] source destination	Synchronizes files and directories between two locations.
screen	screen [options]	Manages multiple shell sessions within one terminal.
tmux	tmux [options]	Terminal multiplexer to manage multiple terminal sessions.
htop	htop	Interactive process viewer (an enhanced version of top).
vmstat	vmstat [options]	Reports virtual memory statistics.
iotop	iotop [options]	Monitors disk I/O usage by processes.
iftop	iftop [options]	Displays bandwidth usage on an interface.
arp	arp [options]	Displays or modifies the ARP (Address Resolution Protocol) cache.
arping	arping [options] host	Sends ARP requests to hosts to discover MAC addresses.
ip	ip [options] object command	Utility for managing network devices, addresses, routing, and more.
ipcs	ipcs [options]	Displays information about IPC (Inter-Process Communication) facilities.
ipcrm	ipcrm [options]	Removes IPC facilities, such as message queues, semaphores, and shared memory.
ss	ss [options]	Displays socket statistics.
traceroute	traceroute [options] host	Displays the route packets take to reach a network host.
tracepath	tracepath [options] host	Similar to traceroute but does not require superuser privileges.
nmap	nmap [options] [target]	Scans networks and hosts for open ports and services.
dig	dig [options] [domain]	Queries DNS servers for information about a domain.
host	host [options] [domain]	Performs DNS lookups.
ethtool	ethtool [options] interface	Displays or changes Ethernet device settings.
iptables	iptables [options]	Configures the Linux kernel’s network packet filtering rules.
ufw	ufw [options]	Uncomplicated Firewall, front-end for iptables to manage firewall rules.
fail2ban	fail2ban-client [options]	Monitors log files and bans IPs that show malicious signs.
logrotate	logrotate [options]	Automatically rotates, compresses, and removes old log files.
journalctl	journalctl [options]	Views logs collected by systemd’s journal service.
rsyslog	rsyslogd [options]	Rocket-fast system for log processing.
lsblk	lsblk [options]	Lists information about block devices.
blkid	blkid [options] [device]	Prints block device attributes like UUID, filesystem type, etc.
hdparm	hdparm [options] device	Gets or sets SATA/IDE device parameters.
lsusb	lsusb [options]	Lists USB devices connected to the system.
lspci	lspci [options]	Lists all PCI devices.
modprobe	modprobe [options] module	Adds or removes a module from the Linux kernel.
lsmod	lsmod	Displays loaded kernel modules.
insmod	insmod module	Inserts a module into the Linux kernel.
rmmod	rmmod module	Removes a module from the Linux kernel.
depmod	depmod [options]	Generates modules.dep and map files for kernel modules.
mkinitcpio	mkinitcpio [options]	Creates an initial ramdisk environment.
mkinitrd	mkinitrd [options]	Creates an initial ramdisk for preloading modules during boot.
dracut	dracut [options]	Another tool to generate initramfs images.
setfacl	setfacl [options] [file]	Sets file access control lists (ACLs).
getfacl	getfacl [options] [file]	Gets file access control lists (ACLs).
chattr	chattr [options] [files]	Changes file attributes on a Linux filesystem.
lsattr	lsattr [options] [files]	Lists file attributes on a Linux filesystem.
fuser	fuser [options] [files]	Identifies processes using files or sockets.
inotifywait	inotifywait [options] [file]	Waits for changes to files using inotify.
inotifywatch	inotifywatch [options] [file]	Watches changes to files using inotify.
ionice	ionice [options] [command]	Sets or gets the I/O scheduling class and priority of a program.
renice	renice [options] [priority] [PID]	Alters the priority of running processes.
lscpu	lscpu	Displays information about the CPU architecture.
lsns	lsns [options]	Lists information about Linux namespaces.
unshare	unshare [options] [command]	Runs a program with some namespaces unshared from the parent.
chroot	chroot [new root] [command]	Changes the root directory for a command or interactive shell.
pivot_root	pivot_root [new root] [put old]	Changes the current root filesystem.
dd	dd if=[source] of=[destination] [options]	Converts and copies files.
shred	shred [options] [file]	Overwrites a file to hide its contents, making recovery difficult.
stat	stat [options] [file]	Displays detailed information about a file or file system.
namei	namei [options] pathname	Follows a pathname until a terminal point is reached, showing the directory entries found along the way.
findmnt	findmnt [options]	Finds a filesystem, listing mount points.
hdparm	hdparm [options] [device]	Gets or sets SATA/IDE device parameters.
dmidecode	dmidecode [options]	Fetches and decodes the DMI table (hardware information).
lsscsi	lsscsi [options]	Lists information about SCSI devices.
lsblk	lsblk [options]	Lists information about block devices.
wget	wget [options] [url]	Retrieves files from the web using HTTP, HTTPS, and FTP.
curl	curl [options] [url]	Transfers data from or to a server using various protocols.
aria2c	aria2c [options] [url]	Downloads files from the web with multi-threading and parallelization.
jq	jq [options] [file]	Processes JSON data, like sed for JSON.
envsubst	envsubst [options] [file]	Substitutes environment variables in shell format strings.
rev	rev [file]	Reverses lines of a file or input.
column	column [options] [file]	Formats text into columns.
hexdump	hexdump [options] [file]	Displays file contents in hexadecimal, decimal, octal, or ASCII.
xdelta3	xdelta3 [options]	Computes differences between files, commonly used for patching.
asciinema	asciinema [command]	Records and shares terminal sessions, with playback in the browser.
zless	zless [file]	Views compressed text files with paging (like less).
xxd	xxd [options] [file]	Creates a hex dump or does the reverse.
units	units [options]	Converts between different units of measurement.
cal	cal [options]	Displays a simple calendar.
factor	factor [number]	Prints the prime factors of a number.
seq	seq [options] [first] [increment] [last]	Generates a sequence of numbers.
bc	bc [options]	Arbitrary precision calculator language.
dc	dc [options]	Reverse-polish notation calculator.